Cyanuric acid derivatives as finish additives

ABSTRACT

CYANURIC ACID DERIVATIVES AS ADHERSION PROMOTING AGENTS ARE ADDED TO THE FINISH OR SPINING COMPOSITION APPLIED TO TIRE YARN USED IN MAKING TIRE REINFORCING CORD AS A MEANS OF PROMOTING ADHESION BETWEEN THE CORD AND THE RUBBER WHEN USING A CONVENTIONAL R/F/L ADHESIVE.

United States Patent C) 3,718,587 CYANURIC ACID DERIVATIVES AS FINISH ADDITIVES Roop S. Bhakuni, Copley, and Joseph L. Cormany, .lr., Akron, Ohio, assignors to The Goodyear Tire & Rubber Company, Akron, Ohio N Drawing. Filed Oct. 5, 1970, Ser. No. 78,251 Int. Cl. D06m 13/34 US. Cl. 2528.6 1 Claim ABSTRACT OF THE DISCLOSURE Cyanuric acid derivatives as adhesion promoting agents are added to the finish or spinning composition applied to tire yarn used in making tire reinforcing cord as a means of promoting adhesion between the cord and the rubber when using a conventional R/F/L adhesive.

This invention relates to, an improved tire yarn finish and to an improved laminate of rubber reinforced with a cord made of the yarn coated with the finish containing an adhesion promoting agent which promotes a bond between the cord and the rubber as in a pneumatic tire when using a conventional R/F/L adhesive applied to the finish treated cord prior to embedment in the rubber.

Pneumatic tires are being subjected to increasingly severe operating conditions, especially high speeds, heavy loads, and accelerated braking and the performance of the tire under these conditions depends in large part upon the durability of the adhesive bond developed between the reinforcing cord and the rubber being reinforced. The bond is formed between active sites in the rubber and on the surface of the cord. The filaments in the yarn used in making the cord are coated with a finish to provide proper lubrication during the drawing and twisting opera- .tions in making the cord. It has been observed that the finish interferes with.maximum bonding of the cord to the rubber.

It has now been discovered that this difiiculty can be overcome without loss of any function performed by the finish by adding an adhesion promoting agent to the finish.

Even though the adhesion promoting agent is added to the finish, the finish still achieves a satisfactory lubrication of the filaments with a minimum of friction throughout various drawing, spooling, winding, transporting,

twisting, cording, weaving and similar textile operations while still providing improved bonding between the cord and the rubber.

nerto the cord.

The tire yarn finish base coating composition of this invention may be applied to many types of tire yarn including such natural fibers as cotton, regenerated cellulose fibers such as rayon, synthetic fibers such as polyamides and known generally as nylon, synthetic fibers of polyacrylonitrilc generally known as acrylon, and synthetic fibers of polyesters, specifically fibers of polyethylene terephthalate known generally bythe trade names Dacron, Vycron, etc.,

Finishes useful in this invention are those used in the fiber industry primarily as a lubricant to minimize friction between the filaments and metal rolls during the drawing operation. Generally these finishes comprise a lubricating oil, an antistatic agent, and an emulsifier. The lubricating oils include such substances as palm oil, coconut oil, cottonseed oil, mineral oil, glycerides, polyglycol esters, butyl stearate, octyl stearate, esters of oleic acid, trimethylol propane/caprylic acid esters, Z-methyl- 2-propyl-propane diol-l,3-dilaurate and 2-ethyl-2-butylpropane diol-1,3-dilaurate. These lubricants are dispersed in water preferably with the aid of an emulsifying agent including such surface active organic compounds as the polyethoxylate of fatty acids, higher fatty alcohols, sorbitol esters or sorbitans, phosphate esters, sulfonated aromatic petroleum hydrocarbons, sulfonated naphthenates, sulfated vegetable oils, polyoxyethylene esters and others, polyglycerol esters and glycerol mono-di-fatty acid esters.

The finish may also contain an antistatic agent to reduce the electrostatic charge of the filament during its processing into a cord or fabric. Examples useful in this invention include such cationic agents, as quaternary ammonium-, pyridinium-, imidazolinium-, and quinolinium-, and quinolinium function, phosphated alcohols and ethoxylated amides.

Water miscible organic solvents such as benzene may also be used in forming the finish for such lubricants as paraffin oils, i.e., saturated aliphatic hydrocarbons boiling in the gasoline range.

The nonionic emulsifying agent are referred to in detail by Swartz et al. in Surface Active Agents published by Interscience Publications Incorporated (1949) starting at page 202, and their use with textile lubricants is described in detail by Swartz et al. in Surface Active Agents and Detergents, volume II, by Interscience Publication Incorporated (1958) starting at page 596. The terms fatty acids and fatty alcohols used in connection with describing the emulsifying agents refer to fatty acids and their corresponding alcohols having an aliphatic hydrocarbon chain of from C-8 to 0-18 or more and are usually derived from natural sources and are usually mixtures of various chain length but the corresponding synthetic compounds may also be used.

The finish is prepared generally by mixing a blend of the lubricating oil with water to a 25 percent solids concentration and then adding the adhesive bond promoting agent to the oil-water mixture, or to the oil prior to mixing with water, and forming an emulsion thereof in warm water and adding sufficient alkali if necessary to adjust the pH from about 8.3 to about 8.5.

It has been found that derivatives of cyanuric acid will produce the desired improvement in bond strength between the rubbcr and the polyester tire cord when added to the finish. The cyanuric acid derivatives have the general formula wherein R is hydroxyethyl and allyl radicals having the formula CH CH OH (commonly referred to as THEIC) and CH -CH=CH (commonly referred to as TAIC) respectively.

The adhesion promoting agent is added to the finish in amounts from about .05 parts to about 30 parts per parts by weight of lubricating oil present. The finish when applied to the filament is present in an amount between about .3 to about 1.5 parts per 100 parts of filament. The adhesion promoting agent may be added to the finish by blending into the oil or by blending into the water before or after the oil is added to the water or dissolved in a solvent and then blended into the oil. The pH of the mixture is to be adjusted as noted before depending upon the adhesion promoting agent and emulsion stabilizer used.

The proportions of the components of the tire yarn finish of this invention may vary over a wide range. In general, finish compositions may be present in the following general amounts based on the total solids present.

Amount, percent Preferred Ingredients Range Lubricant 70 60-75 Antistatic agent 20 30 Emulsifier 10 10-20 emulsion of the finish on the filament at a point below the exit end of a 190 hole spinneret. The filaments are then spun at a spinning speed of 150 yards per minute to give a single spun yarn having a total denier of approximately 7800, which yarn is then passed to a pair of rotating heated rolls and then passed around a pair of heated draw rolls rotating at a speed to impart a draw ratio of about 6 to 1 to give a total denier of approximately 1300 and then wound on a bobbin. The yarn is plied 8 turns per inch, 3 plies are then twisted in reverse direction 8 turns per inch to form a cord referred to as 1300/ 3.8/8.

The polyester cord having the modified finish of this invention is then treated with a 20 percent solids dispersion of a conventional R/F/L adhesive composition made in accordance with the following formula in amount sufficient to give a dry solids pick up from 6 to 7 percent.

R/ F/ L adhesive Ingredients: Parts Resorcinol 98 Formaldehyde (37%) 53 Terpolymer rubber latex of styrene/butadiene- 1,3/viny1pyridine /70/15 (41%) 1152 Water 543 The R/F/L adhesive composition was prepared by adding 98 parts of the resorcinol to 196 parts of water, followed by the addition of 53 parts of formaldehyde. The resulting mixture was aged for one hour and then 1152 parts of terpolymer rubber latex was added. The resulting mixture was aged for a period of 72 hours. After aging, the balance of the water was added. To 65 parts of this R/F/L composition was added 35 parts of a resinous formula: 110 parts of resorcinol, 25 parts by volume of formalin (37% formaldehyde in methanol and water), and parts by volume of water was reacted together in a reaction vessel equipped with both heating and cooling coils, a reflux condenser and a suitable agitator. The mixture was heated to reflux temperature (100 C.) and allowed to remain at this temperature for 15 minutes, after which an additional 30 parts by volume of formalin was added to the reaction mixture over a period of 10 minutes. After being refluxed for an additional 30 minutes, the resin formed in the reaction vessel was allowed to cool to room temperature. A thick, syrupy resin (for convenience referred to as Resin A) containing 60 percent solids, a viscosity of 750 cps. and a pH of 7 was obtained.

Twenty parts of the Resin A described above is reacted with 6 parts of polymethylene polyphenylisocyanate for 48 hours at 72 F. At the end of this time, the resulting reaction mixture is treated with 0.1 part of sodium hydroxide and parts of water. The resulting neutralized resin-blocked polyisocyanate was allowed to age for 8 hours to produce a clear supernatent layer of soluble resin-blocked polyisocyanate (and for convenience to be referred to as Resin B).

To 65 parts of the R/F/L adhesive composition decribed above is added 35 parts of Resin B and allowed to age at 72 F. for 4 hours.

The polyester cord 1300/ 3 (Dacron) is passed through a dip tank containing this adhesive. The dipped cord is then dried at 450 F. and embedded in rubber compounded as shown below.

Parts by weight Amount May be Ingredients used used 1. Natural Rubber 70 0-100 2. OE/SBR 1778 (styreue/butadiene-1,3 23.5/ 76.5 copnlymer) (plus 37% parts oil per 100 SBR) 27. 5 100-0 3. Cis 1.4-polybutadiene 10 0-50 4. Carbon black (reinforcing agen 40 25-100 5. Zine oxide (activator of cure) 4 2-10 6. Stearic acid (activator of cure) 2 1. 5-3. 0 7. Primary accelerator (2,2-dithiobisbenzothiazole) 1. 25 5-3.0

8. Pine oil (softener) 10 2-50 9. Secondary accelerator (tetramethyl thiuram disulfide) 10 05-1. 0

10. Antioxidant 6 1 4 11. Sulfur (vulcanizing agent the formulation set forth above, a masterbatch of ingredients 1 and 2 are made with the carbon black and mixed on a mill to a temperature of about C. and may be mixed at a temperature as high as C. The resulting carbon black masterbatch is then cooled and the remaining compounds are mixed into the batch in the order indicated above to a temperature of about 70 C. and may be mixed at a temperature as high as 100 C.

The following ratings are based on a control using the identical finish, cord and rubber but without the addition of the adhesion promoting agent to the finish. Amount of additive is in percent by weight based on the total weight of the finish solids present in the finish.

l Peel adhesion is determined in the following manner. Onto the surface of a 12 mil thick sheet (12" x 12) of rubber (MRS) is laid the treated cords at the rate of 18 per inch which are then covered with a second sheet (12 x 12) of 12 mil gauge rubber (MRS). This sandwich arrangement of rubber cord and rubber is then doubled onto itself with a piece of Holland cloth extending one inch into the doubled assembly from the open end from which assembly is clicked 1 x 3 samples, which samples are then cured in a mold at 340 F. for 10 minutes. The cured sample is then placed in an Instron machine, heated at 250 F. and the two strips of rubber separated by the Iiolland cloth are then moved in opposite directions at the rate of 2 per minute to determine the average force (A) required to separate the remaining portion of the sample. Depending on the adhesion developed between the cord and rubber, separation either occurs at the rubber/rubber interface or the rubber/cord interface or at both in varying amounts. After separation has been completed, the amount of rubber remaining (B) on the cord is determined by visual inspection.

Z Fatigue data based on heat durability wxs obtained on a tube of rubber reinforced with the cord treated in the manner described herein and Ze2sted in accordance with the requirements of ASIM D-885-59T,

The present invention may be used in the manufacture of a pneumatic tire of conventional present day design as shown, for example, in such U.S. Pats. as 3,157,218;

3,160,191; 3,160,192; 3,217,778; 3,225,810; 3,225,812; 3,244,215; 3,253,633 and 3,253,638 all of which show a vulcanized rubberized fabric carcass of generally toroidal shape having a tread portion superimposed and bonded to the crown area of the carcass and plies of rubberized fabric forming sidewalls extending from the tread over the carcass to the bead portion.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What is claimed is:

1. A tire yarn finish base coating composition consisting essentially of a lubricating oil, an antistatic agent, an emulsifier, water and an adhesion promoting agent having the general formula 3,297,468 1/1967 Macura et al. 11747 3,248,258 4/1966 Coats 2528.9 X 3,051,594 8/1962 Aitken 117--138.8 2,947,736 8/ 1960 Lundberg 260248 3,065,231 11/ 1962 Frazier et a1. 260-248 3,088,948 5/ 1963 Little et al 260248 3,402,127 9/1968 Mowe 2528.8 X

HERBERT B. GUYNN, Primary Examiner US. Cl. X.R.

20 57-153, 164; l17138.8 B, 138.8 F, 139.5 C.Q.; 156 

